The paper clarifies what constitutes a substantial manipulation of cells or tissues, defines non-homologous use of cells or tissues, clarifies when drugs based on recombinant viral vectors are considered as vaccines against infectious disease and not as gene-therapy medicinal products, and sets criteria for combined ATMP classification.

An ATMP classification offers incentives such as fee reductions and is usually the first connection between EMA and ATMP developers. According to the agency, it can help sponsors identify applicable regulatory framework for their drug development path.